Device for cleaving an optical fibre

ABSTRACT

A device for cleaving an optical fibre includes a fixing mechanism to fix a fixing element to the optical fibre, and a cleaving mechanism to cleave the optical fibre. The fixing element may be a ferrule, and the fixing element may be fixed to the fibre such that the fibre extends through the fixing element. The cleaving mechanism cleaves the fibre preferably when the fixing element has been fixed to the fibre. The cleaving device may be a hand-held, and hand-operated, tool. The device may enable the possibility of automatic preset positioning and/or orienting of the cleaved fibre end face (which may be angled to the axis of the fibre) with respect to the fixing element. Attachments may be provided for holding the fibre and fixing element during the cleaving operation and for holding a connector body while the fixing element with the cleaved fibre is inserted into the connector.

CLAIMS FOR PRIORITY AND RELATED APPLICATIONS

The present application is a National Phase application ofPCT/GB2003/002889 filed on Jul. 4, 2003 and published in English(International Publication No. WO 2004/008205), which claims priorityfrom GB Application No(s). GB 0216434.1 filed on Jul. 16, 2002; GB0216436.6 filed on Jul. 16, 2002; GB 0216435.8 filed on Jul. 16, 2002;GB 0303703.3 filed on Feb. 18, 2003 and GB 0307762.5 filed on Apr. 4,2003, the disclosures of which are incorporated herein by reference intheir entireties.

FIELD OF INVENTION

The present invention relates to a device for cleaving an optical fibre,and in particular such a device in the form of a hand-held tool.

BACKGROUND OF THE INVENTION

When splicing optical fibres mechanically, for example by means of apermanent optical fibre connector, it is generally necessary to preparethe end faces of the fibres to ensure that a satisfactory splice, havinglow optical losses, is formed.

Co-pending United Kingdom Patent Application No. 0216435.8 (B429) filedby the present applicant discloses an optical fibre connector in which asplice between two optical fibres is formed by means of two ferrulesinserted into a connector body, each of which is pre-fixed to arespective optical fibre in a preset orientation with respect to anangled end face of the optical fibre. (By “angled end face” is meant anend face of the optical fibre that is not perpendicular to thelongitudinal axis of the fibre.) The ferrules can be inserted into theconnector body only in a preset orientation about their axes, andtherefore the relative orientations of the two fibre end faces arepredetermined to ensure an intimate and low-loss contact between the endfaces.

International Patent Application WO 98/54608 discloses a tool for theangled cleaving of optical fibres. The tool cleaves an optical fibre byclamping the fibre under tension by means of two clamping blocks,displacing the fibre between the clamping blocks by means of an anvil sothat the displaced part of the fibre experiences a localised shearforce, and scoring the fibre. Because the scored part of the fibre isunder both tension and shear, the fibre cleaves at an angle away fromthe perpendicular to the fibre axis. The cleaving tool may be used tocleave an optical fibre that has a ferrule attached to it prior to theinsertion of the fibre into the tool. In addition, forpolarisation-maintaining (PM) optical fibres, a ferrule that has beenpre-attached to such a fibre may be placed in the cleaving tool in afixed orientation so that the angle of cleave is in the correctorientation with respect to the polarisation axis of the PM opticalfibre.

SUMMARY OF THE INVENTION

According to a first aspect, the present invention provides a device forcleaving an optical fibre, comprising a fixing mechanism to fix a fixingelement to the optical fibre, and a cleaving mechanism to cleave theoptical fibre.

A second aspect of the invention provides a device according to thefirst aspect of the invention, comprising a hand-held tool.

At least in the broadest aspects of the invention, the fixing elementmay be any element (or component) that is fixed to the optical fibre bythe fixing mechanism. The fixing element may, for example, be an opticalfibre connector or a part thereof, but in the broadest aspects of theinvention the fixing element is not so limited.

It is presently preferred for the fixing element to be in the form of aferrule. The ferrule (or other fixing element) may, for example, be usedto secure an optical fibre to an optical fibre connector. However, thebroadest aspects of the term “ferrule” are not intended to be limited tosuch use.

The fixing element may generally be fixed to the optical fibre in anyconvenient way by the fixing mechanism. Preferably the fixing element isfixed to the optical fibre such that the fibre extends through thefixing element. In the broadest aspects of the invention, however, thefibre need not extend through the fixing element when fixed thereto.

In the description that follows, for the sake of convenience the fixingelement is generally referred to as a ferrule. It is to be understood,however, that (at least in the broadest aspects of the invention) thefixing element need not comprise a ferrule.

The invention has the advantage that because the device both fixes afixing element (e.g. a ferrule) to an optical fibre and cleaves thefibre, two steps in the process of splicing optical fibres (for example)may be carried out by a single device, thus simplifying and increasingthe speed of the splicing process.

At least in the broadest aspects of the invention, the cleavingmechanism of the device may cleave the optical fibre prior to, orsubstantially simultaneously with, the fixing of the fixing element tothe fibre by the fixing mechanism. Preferably however, the cleavingmechanism of the device cleaves the fibre when the fixing element hasbeen fixed thereto. More preferably, the cleaving mechanism of thedevice is able to cleave the fibre only when the fixing element has beenfixed thereto.

Because the device preferably cleaves the fibre once the ferrule (orother fixing element) has been fixed to the fibre, this enables thepossibility of the cleaved end face of the fibre being produced at apreset position along the fibre with respect to the ferrule and/or at apreset orientation with respect to the ferrule. This can be extremelybeneficial, because it can enable the quick and accurate formation of alow-loss (high return loss) optical fibre splice, by bringing the angledcleaved end faces of the optical fibres physically into contact in akeyed orientation. In particular, because the device according to theinvention enables the possibility of such preset positioning and/ororienting of the cleaved fibre end face with respect to the ferrule, itsubstantially removes the need for skill and judgement on the part ofthe technician carrying out the splicing operation to perform thisoperation. Consequently, the invention can improve the quality andconsistency of optical fibre splices. Optical fibres that have beenprepared by means of the device according to the invention may, forexample, simply be inserted into a connector body arranged such thatmere insertion of the ferrules fixed to the fibres by the device ensuresthe correct relative positioning of the end faces of the fibres toachieve a low-loss splice. Such a connector may, for example, be asdisclosed in UK Patent Application No. 0216435.8.

The fixing mechanism of the device preferably is a crimping mechanism tocrimp the ferrule (or other fixing element) and thereby fix it to thefibre.

As mentioned above, the fixing mechanism and the cleaving mechanism ofthe device according to the invention preferably are arranged such thatthe fibre is cleaved, and consequently an end face of the fibre isproduced, at a preset position along the fibre with respect to theferrule.

Advantageously, the cleaving mechanism may cleave the optical fibre suchthat the end face produced is oriented at a non-perpendicular angle withrespect to a longitudinal axis of the fibre.

Preferably the fixing mechanism and the cleaving mechanism of the deviceare mutually arranged such that the fibre end face produced by thecleaving mechanism is at a preset orientation with respect to theferrule. Consequently, the fixing mechanism preferably includesorientation determining means arranged to orient the ferrule at apredetermined orientation about the longitudinal axis of the fibre, withrespect to the cleaving mechanism. The orientation determining meansmay, for example, comprise a non-circular orifice arranged to receivetherein a ferrule having a corresponding non-circular cross-section. Thedevice preferably includes (first) closing means that closes thenon-circular orifice when the device is not in operation.

Advantageously, the device may include an aperture (preferably on anopposite side of the device to the non-circular orifice) by which aseparated end portion of the cleaved optical fibre may be removed fromthe device. The device preferably includes (second) closing means thatcloses the aperture when the device is not in operation.

Such closing means substantially prevent dust and other contaminantsentering the device, which could otherwise adversely affect itsperformance. In this way, the device may be substantiallymaintenance-free.

The fixing mechanism of the device preferably grips the ferrule whilethe cleaving mechanism cleaves the fibre. Advantageously, therefore, thefixing mechanism preferably grips the fibre (via the ferrule) while thecleaving mechanism cleaves the fibre. Additionally, the fixing of thefibre in a ferrule, by the fixing mechanism, may provide axial pullresistance and torsion resistance to the fibre.

The cleaving mechanism of the device preferably includes a clampingmechanism that grips the fibre while the fibre is cleaved. Preferablythe clamping mechanism grips the fibre prior to, and during, thecleaving of the fibre. More preferably, the clamping mechanism maycomprise a pair of tapes between which the fibre is gripped, the tapespreferably being arranged such that for each fibre that is cleaved bythe device a different position along the tapes is used to grip thefibre.

Preferably the fibre is placed under tension and/or shear by thecleaving mechanism while the fibre is cleaved. The cleaving mechanismpreferably includes an anvil that causes the fibre to be bent while thefibre is cleaved. The cleaving mechanism preferably includes a scoringblade arranged to score the fibre, causing a crack to propagate throughthe fibre, thereby cleaving the fibre. The scoring blade preferably isarranged such that for each fibre that is cleaved by the device, adifferent position on the blade is used to score the fibre.

The device preferably includes a lifetime indicator that indicates thenumber of cleaves that have been made by the device since a deviceset-up procedure and/or the number of cleaves remaining for the device,preferably until a device re-set procedure. The device set-up procedureand/or re-set procedure preferably comprises changing the blade and/orthe tapes of the cleaving mechanism.

In at least some preferred embodiments of the invention, the device isarranged to cleave a plurality of optical fibres substantiallysimultaneously. Advantageously, therefore, the fixing mechanism may bearranged to fix one or more fixing elements to the plurality of opticalfibres, preferably substantially simultaneously. The plurality ofoptical fibres may, for example, comprise ribbon fibre.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will be described, by way of example,with reference to the accompanying drawings, of which:

FIG. 1 shows an embodiment of an optical fibre cleaving device accordingto the invention, in the form of a hand-held tool;

FIG. 2 shows the device of FIG. 1 from a reverse angle;

FIG. 3 shows part of the interior of the device of FIGS. 1 and 2;illustrating the crimping mechanism;

FIG. 4 shows a detail of another view of the interior of the device;illustrating the crimping mechanism;

FIG. 5 shows another detail of the interior of the device;

FIG. 6 is a schematic diagram of the main components and the functioningof the cleaving mechanism of the device;

FIG. 7 is a detail of part of the interior of the device, illustratingthe cleaving mechanism;

FIG. 8 is a detail illustrating the cleaving mechanism of FIG. 7 from areverse angle;

FIG. 9 shows part of both the exterior and the interior of the device,in particular the cleaving mechanism;

FIG. 10 shows a detail of another part of the cleaving mechanism of thedevice, in particular relating to the scoring blade;

FIG. 11 shows a reverse view of the device, showing part of the scoringblade mechanism; and

FIG. 12 shows an example of a suitable ferrule to be crimped to anoptical fibre by means of the device.

FIG. 13 is a three-dimensional view of an integrated crimp & cleave tool(ICCT) (schematically indicated with an attached “goose-neck”positioning clamp and attached CKAH, ASAH, and guide rails).

FIGS. 14 to 19 illustrate successive steps in using the attached CKAHand ASAH.

FIGS. 20 to 23 illustrate the re-useable spring aspect of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

FIG. 1 shows an exterior view of a preferred embodiment of an opticalfibre cleaving device 1 according to the invention. The device 1 is inthe form of a hand-held and manually operated tool. The tool comprises amain part 3 and a pair of handles 5 a and 5 b.

The handles 5 a and 5 b are sized and shaped to be gripped by the handof a user. Squeezing the handles together operates the crimpingmechanism whereby a ferrule is fixed to an optical fibre by crimping theferrule around the fibre, as described below. The handles 5 a and 5 bhave an over-centre camming action whereby they lock in place whensqueezed together by a preset angle. The locked handles may be unlockedby means of a release lever 7.

The main part 3 of the device 1 comprises a slidable outer housing part9 that operates the cleaving mechanism of the device whereby an opticalfibre to which a ferrule has been fixed is cleaved to produce acontrolled end face of the fibre. Subsequent to operating the crimpingmechanism by squeezing the handles 5 a and 5 b together, the user movesthe slidable part 9 with respect to the remainder of the device, in adirection away from the handles (as indicated by arrow A). This movementof the part 9 causes the cleaving mechanism of the device to clamp andcleave the optical fibre, as described below. Preferably the part 9 canbe moved (thereby actuating the cleaving mechanism) only once thehandles 5 a and 5 b have been squeezed together, so that the cleavingoperation can take place only once the crimping operation has takenplace.

In order to carry out these operations, the user first inserts theferrule at a predetermined orientation into the device and feeds astripped optical fibre through the ferrule, into an insertion hole 11 ina front plate 13 of the device 1. An opposite side of the device, shownin FIG. 2, includes another aperture 14 by which a separated end portionof the cleaved optical fibre may be removed from the device.

The ferrule that is inserted into the device may comprise part of aholder/ferrule assembly as disclosed in UK Patent Application No.0216435.8, the entire disclosure of which is incorporated herein byreference. An example of a suitable ferrule 15 for use with the deviceaccording to the invention is illustrated in FIG. 12. The ferrule 15,which is generally circular in cross-section, includes a flat portion 17on its peripheral surface so that the orientation of the ferrule aboutits axis (and the axis of the optical fibre 19) may be preset. Inparticular, the cross-sectional shape of a front portion of the ferruleis arranged substantially to match that of a non-circular (andpreferably generally “D”-shaped) aperture 21 in a plate 23 locatedbehind the front plate 13 of the device (see FIG. 5).

The aperture 21 constitutes the orientation determining means of thedevice as referred to previously, by which the ferrule is oriented at apredetermined orientation with respect to the cleaving mechanism of thedevice. Plate 23 and aperture 21 are shown in FIG. 5, and areschematically shown in cross-section in FIG. 6. Behind plate 23 is afurther plate 25 containing a smaller diameter aperture 27 that issubstantially coaxial with the D-shaped aperture 21. Smaller aperture 27is arranged to provide a stop for an end of the primary coating 29 of anoptical fibre, which coating will have been stripped away from an endregion 31 of the fibre 19, as shown schematically in FIG. 6. The ferrule15 is inserted into the insertion hole 11 in the front plate 13 of thedevice and a stripped fibre 19 is fed through the ferrule. The front ofthe ferrule 15 butting against the back of the D-shaped orientationdetermining aperture 21 of plate 23, and the front of the stripped awayprimary coating of the fibre butting against the aperture 27 in thefurther plate 25.

Referring now to FIGS. 3 and 4, with the ferrule 15 and the opticalfibre 19 so inserted into the device 1, the handles 5 a and 5 b aresqueezed together until they lock in place. This action causes crimpingblocks 33 to move relatively closer together by a predetermineddistance, thereby crimping the ferrule around the fibre with apredetermined force, and thus fixing the ferrule to the fibre.

Subsequent to this crimping/fixing step, the slidable outer housing part9 of the device is moved, by the user, away from the handles 5 a and 5b, in the direction of arrow A in FIG. 1. This sliding movement causesvarious operations of the cleaving step to be performed by the device,by which the optical fibre is cleaved to produce a non-perpendicular endface of the fibre having a preset orientation and longitudinal positionwith respect to the ferrule.

The initial operation of the cleaving step comprises clamping of theoptical fibre by means of a clamping mechanism comprising a pair ofclamp blocks 35 a and 35 b, and a pair of spooled tapes 37 a and 37 bthat extend over respective clamping surfaces of the clamp blocks. Asmay be understood from FIG. 7, movement of the slidable part 9 in thedirection of arrow A causes the upper (as illustrated) clamp block 35 ato move downwards (as indicated by arrow B) towards the lower clampblock 35 b due to a contact between an upper surface of the upper clampblock with an inclined surface (i.e. inclined with respect to thedirection of movement of the part 9) of a cooperating part 39 whichmoves with part 9. Since the tapes 37 a and 37 b extend over therespective clamping surfaces of clamp blocks 35 a and 35 b, the opticalfibre is trapped between the tapes 37 a and 37 b (with the optical fibreand the tapes together trapped between the clamp blocks). The tapes 37 aand 37 b preferably are polymeric, for example polyvinyl chloride (PVC).The tapes preferably are compressible and preferably provide a highdegree of grip by which they grip the optical fibre in their clampingposition.

The use of such tapes has several benefits. Firstly, the high degree ofgrip on the optical fibre enables the fibre to be placed under tensionfor the cleaving operation (described below). Preferably, an axial pullresistance in the range 2.5 to 4.0 N is provided by the tapes. Secondly,the compressibility of the tapes generally prevents the optical fibrebeing damaged when clamped. Thirdly, the tapes 37 a, 37 b preferably areindexed such that they present a fresh surface between the clamp blocks,for clamping an optical fibre, each time the part 9 is moved to operatethe cleaving mechanism. This indexing of the tapes is achieved by meansof cog wheels 43 a and 43 b as shown in FIG. 8 (and part of wheel 43 bis also visible in FIG. 7). The cog wheels 43 a and 43 b are connectedto take-up reels 41 a and 41 b respectively, and are rotated through apreset partial revolution by means of the slidable housing part 9 beingmoved back towards the handles 5 a, 5 b (in the opposite direction tothat of arrow A) after the cleaving operation has been completed. Inthis way, the tapes are wound-on by a preset amount (from their spoolsto their take-up reels) between each fibre cleaving operation.Consequently, any dust generated by fibre cleavages is carried away bythe tapes between each cleaving operation, ensuring that every opticalfibre cleaved by the device experiences substantially the same clampingconditions, thus ensuring consistency between optical fibres.

Once an optical fibre is clamped between the tapes 37 a, 37 b and theclamp blocks 35 a, 35 b, the continued movement of the slidable housingpart 9 in the direction of arrow A causes an anvil 45 adjacent to thelower clamp block 35 b to be raised in the direction opposite to that ofarrow B (as illustrated in FIGS. 7 and 9). This movement of the anvil 45is achieved by means of another cooperating part 47 having an inclinedsurface, which is lifted upwardly by means of a peg 49 that moves withpart 9. Substantially simultaneously with this movement of the anvil 45,the clamp blocks 35 a, 35 b, which at this stage are clamping theinserted optical fibre, together move slightly away from the anvil in adirection along the axis of the fibre (i.e. backwards from the viewpointof FIG. 7). This is achieved by means of a member 51 (as shown in FIG.8) that slides together with part 9 and cooperates with a resilientmember 53 to urge a plate 55 laterally with respect to the direction ofarrow A (i.e. backwards from the viewpoint of FIG. 8). The clamp blocks35 a and 35 b are moved away from the anvil by this movement of theplate 55, and this puts the section of the clamped optical fibreextending between the ferrule 15 and the clamp blocks 35 a, 35 b undertension. The fibre is also subjected to a localised shear force due toit being displaced by the upward movement of the anvil 45.

Once the clamped optical fibre has been placed under tension and shear,further movement of the slidable part 9 in the direction of arrow Acauses a first trigger element 54 (as shown in FIG. 10) attached to thepart 9 (only a portion of which is shown in FIG. 10) to knock a tooth 58of a rotatable member 60. This causes the rotatable member 60 to rotatein the direction of arrow E, causing another tooth 62 of the rotatablemember 60 to impinge on a pivoted member 64 which is arranged to pivotabout pivot point 66; consequently, member 64 pivots about point 66 inthe direction of arrow D. A pivoted scoring blade 61 is attached to thepivoted member 64, and therefore the pivoting of this member also causesthe scoring blade to rotate as indicated by arrow D, thereby scoring theoptical fibre at a predetermined position along the fibre where thefibre is under both tension and shear. The resultant of the tension andshear forces applied to the fibre, together with the scored line ofweakness caused by the scoring blade 61, cause the fibre to cleavesubstantially along a plane that is non-perpendicular to the axis of thefibre.

The movement of the part 9 in the direction of arrow A also causes asecond trigger element 56, also attached to part 9 (see FIG. 10), torotate a ratchet wheel 68 by a partial revolution (preferably one toothof its toothed periphery). The ratchet wheel 68 is connected by a seriesof cogs to indexing wheels 57, shown in both FIG. 10 and FIG. 11. Asshown in FIG. 11, a spiral wheel of the indexing wheels 57 causes aslidable bar 59 to move linearly in the direction of arrow C. Eachmovement of the bar 59 is by only a tiny amount for each actuatingmovement of the part 9. This movement of the slidable bar 59 causes thescoring blade 61 to move by a tiny amount, such that the starting pointof the rotation of the scoring blade is very slightly different eachtime the device is used to cleave an optical fibre. In this way, thepart of the scoring blade which scores an optical fibre is “indexed”,i.e. a different part of the blade is used each time an optical fibre iscleaved. Consequently, each optical fibre experiences an unused part ofthe scoring blade, and consequently blunting of the blade over time doesnot cause a variation in the cleavage of optical fibres by the deviceover time. Preferably the distance by which the blade moves (to presenta new starting position) each time the device is used, is so tiny, thathundreds or thousands (e.g. 5,000) cleavage operations can be performedby a single blade. The blade preferably comprises a diamond cuttingedge.

Subsequent movement of the slidable housing part 9 back towards thehandles 5 a, 5 b, causes the various components of the cleavingmechanism of the device to return to their starting positions, andcauses the tapes 37 a and 37 b to be wound-on a specified length suchthat they present a fresh surface for the subsequent clamping operation.Pushing the release lever 7 in the direction of arrow A then releasesthe handles 5 a and 5 b which preferably open under the action of aresilient member (e.g. a spring—not shown) thereby opening the crimpblocks 33 and allowing the ferrule 15, and the cleaved optical fibre 19to which it is fixed by crimping, to be removed from the device.

An additional preferred feature of the device 1 to be noted is theflexible arm 63 shown in FIG. 3. The flexible arm 63 enables the deviceto be attached to another piece of equipment, for example an opticalfibre splice closure. The arm 63 may, for example, be a flexibleattachment arm of the type used in some microphone stands (etc) andsometimes referred to as a “gooseneck”.

It will therefore be appreciated that the device according to theinvention may be in the form of tool (for example as illustrated herein,and described above) that may be hand-held and hand-operated. The toolmay conveniently be used by an optical fibre installation/repairtechnician in the field, as well as in the factory.

Additional aspects of the present invention relate to improvements byway of advantageous attachments and methods to be used with theIntegrated Crimp & Cleave Tool (ICCT) hereinbefore described.

One improvement is achieved by attachment to the ICCT of aflexibly-positionable neck and clamp (similar to a “goose-neck” lamp,for example) for the purpose of temporarily attaching the ICCT in aconvenient working position on a telecoms distribution frame or otherapparatus where optical fibres are to be connected. The specificconstruction of the neck and clamp, and the specific means of theirattachment to the ICCT are not critical and require no furtherdescription. One possible arrangement is illustrated in theaforementioned FIG. 3, and another is indicated hereinafter.

Another improvement is an ICCT device wherein a holder is attached tothe ICCT for holding a connector, into which connector, when present inuse, will be inserted a crimped ferrule and cleaved optical fibreprepared by use of the ICCT. The connector, hereinafter referred to asan “Alignment Sleeve Assembly” (ASA), can thus be conveniently held onthe ICCT by the attached ASA Holder (ASAH) for insertion of the ferruleand fibre immediately after crimping and cleaving thereof by the ICCT.Preferably, the ASAH will be rotatably attached to the ICCT forinsertion of a first ferrule and fibre into one end of the ASA, then asecond ferrule and fibre into the other end of the ASA, after rotationof the ASAH to present the said other end for convenient insertion fromsubstantially the same direction as the first.

The crimped ferrule and cleaved fibre are optionally secured in the ASAby means of a ferrule holder, for example as described in our co-pendingBritish patent applications No. 0216435.8 (B429) and No. 0216434.1(B427), both entire disclosures of which are incorporated herein byreference. This self-aligning combination of the ferrule holder,ferrule, and fibre, hereinafter referred to as a “Crimp & Key Assembly”(CKA), may be moved from the crimping-and-cleaving part of the ICCT to aposition for insertion into the ASA by any convenient means, for exampleby the hand-held assembly tool described and claimed in our co-pendingBritish patent application No. 0216436.6 (B428), the entire disclosureof which is incorporated herein by reference. However, in preferredversions of the present improvement, the CKA is held in a CKA Holder(CKAH) moveably attached to the ICCT. This CKAH holds the CKA during thecrimp-and-cleave operation, and is preferably then moveable on acontrolled path, for example by means of rails or other guides, from thecrimp-and-cleave position to bring the CKA into alignment with the ASAwhen held in the ASAH. Thereafter, the CKAH is releaseable to allowinsertion and locking of the CKA into the ASA.

Alternatively, the device according to this invention may have attachedthereto securing means for directly securing the ferrule and the fibreduring and after the crimp and cleave operation in the absence of anyseparate ferrule holder. In this case, the device preferably hastransfer means attached thereto whereby the securing means and thesecured crimped ferrule and cleaved fibre can be moved, preferablyguided by guide means attached to the device, (i) to bring the ferruleand fibre from the crimp-and-cleave position into alignment with an ASAwhen held in the ASAH in use and (ii) to insert the ferrule and fibreinto the ASA in the required orientation with or without a keyingformation on the ferrule, the securing means being releasable after theferrule has been fixed in the ASA in the required orientation.

The invention accordingly also provides a method of coupling opticalfibres using such an alternative form of the device, including the stepsof (a) directly securing a ferrule and a fibre in the said securingmeans during and after the crimp and cleave operation in the absence ofany separate ferrule holder, (b) moving the secured crimped ferrule andcleaved fibre (i) to bring the ferrule and fibre from thecrimp-and-cleave position into alignment with an ASA when held in theASAH in use and (ii) to insert the ferrule and fibre into the ASA in therequired orientation with or without a keying formation on the ferrule,(c) fixing the ferrule and fibre in the ASA in the required orientation,and (d) releasing the securing means.

Our aforementioned co-pending British patent application No. 0216434.1(B427) describes the provision of a resilient member (spring) inside theCKA, between the end of the crimped ferrule and an inner end of theferrule holder, for the purpose of compensating variable lengthtolerances in the two cleaved fibres whose ends are aligned wheninserted into the ASA. Mass production of such CKAs with the internalspring can be undesirably difficult and expensive. It is thereforepreferred to use a CKA wherein the ferrule holder and the resilientlycompressible member are shaped and arranged so that the resilientlycompressible member is removable from the holder after the holder hasbeen attached to the connector body to retain the ferrule in place.Preferably, the ferrule holder and compressible member are shaped andarranged to permit re-use of the compressible member by insertion andremoval thereof in and from a succession of similar CKAs for insertionand attachment to ASA connector bodies. Insertion and removal of thecompressible member via lateral apertures in the ferrule holder body ofthe CKA may be convenient in practice.

A further improvement in the ICCT according to the present inventioninvolves provision of a re-useable resiliently-compressiblefibre-length-tolerance-compensating member, preferably carried by theCKA Holder (CKAH) as hereinafter described, for insertion in andsubsequent removal from a succession of suitably shaped and arrangedCKAs to be inserted into ASAs held in the ASAH attached to the ICCT.

In the alternative form of the invention wherein the ferrule is secureddirectly by the aforementioned securing means, the resilientcompensation for variances in the crimp and cleave tolerances may beprovided, for example incorporated in the securing means, in ways whichwill be apparent to suitably skilled engineers.

Embodiments of the aforementioned improvements will now be described byway of example with reference to FIG. 13–23.

With reference to the drawings, FIG. 13 shows schematically a goose-neckpositioning clamp G attached to the ICCT in a different position fromthat described in the aforementioned FIG. 3.

FIG. 13 also shows guide rail (1), which is fixed with two chamferedscrews 10 and has two locks (a) to hold the CKAH retainer alignedfirstly with the CKA entrance (not visible in this view) to thecrimp-and-cleave part of the ICCT and subsequently with the ASAH (6) atthe top (as shown in this example) of the ICCT;

CKAH retainer (2), which slides vertically up and down on rail (1) andhas two locks (b) to lock the CKAH retainer in two different positionsplacing the CKA (when present in use) in and out of the crimpingentrance of the ICCT and in and out of the ASA (when present in use);

CKAH (3), which slides horizontally to bring the CKA in/out of the saidentrance of the ICCT and the said ASA;

CKAH cover (4), which closes over the CKA (when present) by hinging tohold the metal ferrule horizontally (see FIG. 17);

CKAH retainer stop module (5), which prevents CKAH retainer (2) fromsliding out of guide rail (1);

ASAH (6), which can be rotated 180° after installation of the first CKAin the ASA and can be held in place by two features (c);

ASAH retainer (7), which is fixed by two screws on top of the ICCT;

ASAH cover (8), which holds the ASA (when present) by hinging; and

ASAH fixation screws (9).

The operating steps are illustrated in FIGS. 14 to 19 as follows:

Step 1: Place the ASA in the ASAH and close the cover, the arrangementbeing such that the ASA can be placed in only one orientation and cannotrotate or slide longitudinally in the ASAH;

Step 2: Slide the CKAH backwards, open the cover and place the CKA inthe CKAH;

Step 3: Close the CKA cover to hold the CKA in place;

Step 4: Slide the CKAH towards the ICCT so that the metal ferrule entersthe ICCT, then insert the optical fibre, crimp the ferrule, and cleavethe fibre;

Step 5: Slide the CKAH backwards to remove the crimped ferrule andcleaved fibre from the ICCT, then lock the CKAH to prevent horizontalmovement which might damage the filre during the next step;

Step 6: Slide the CKAH upwards to the ASAH and lock the CKAH in thatposition;

Step 7: Slide the CKAH forward to insert the CKA into the ASA as far aspossible and lock in that position;

Step 8: Open the cover of the CKAH and release the CKA by moving theCKAH downwards;

Step 9: Slide the CKAH backwards as indicated by arrow;

Step 10: Slide the CKA fully into the ASA and lock it by rotating theCKA until it reaches the two diagonal opposed cylindrical“bayonet-fixing” protrusions, afterwards slide the CKAH downwards to theoriginal starting position;

Step 11: Rotate the ASAH, place a new CKA in the CKAH and repeat allsteps again to produce a completed connection of two cleaved fibres inthe ASA, with the D-shape (arrowed) of the CKA ferrules ensuring correctalignment of the cleaved ends. Repeat the whole fibre-connectingoperation as many times as required for the number of ASAs in whichfibres are to be connected.

One possible arrangement according to the aforementioned re-useablespring aspect of the invention will now be described by way of examplewith reference to FIGS. 20 to 23. In this example, the compressiblemember 41 is a bifurcated leaf spring inserted as indicated by arrow Ain FIG. 20 via a suitably-shaped lateral aperture 46 extending toopposite sides of the ferrule holder 39. The spring 41 thus permits thedesired resilient movement of the ferrule 1 in the holder 39 duringinsertion into the ASA connector body (not shown) in the direction ofarrow B. After the ferrule holder 39 is twisted (arrow C) into lockingengagement with the connector, thus bringing the ferrule into fixedengagement with the ferrule holder as described in our aforementionedco-pending Application 0216434.1, the spring 41 is no longer requiredand may be removed, for example by means of an attached flexible memberF schematically indicated.

FIG. 21 illustrates the re-useable spring 41 positioned in the CKAH 3prior to positioning of the CKA (ferrule 1, holder 39, and optical fibreO) therein and closure of the CKAH cover 4. In FIG. 22, the CKA is inposition in the CKAH 3 with the spring 41 inserted into the aperture 46in the holder 39 of the CKA, awaiting closure of the cover 4 to securethe CKA in the CKAH, to be followed by crimping of the ferrule andcleaving of the optical fibre O in the ICCT (not shown). FIG. 23illustrates the opening (arrow D) of the CKAH cover 4 and lowering(arrow E1) of the CKAH 3 to release the CKA after the crimped ferrule 1and the cleaved optical fibre (O) have been inserted, as far as the CKAHmovement (arrow E2) will allow, into the ASA held in the ASAH (see FIG.14). The flexible member F may be attached as schematically indicated toretain the re-useable spring 41 on the CKAH 3, optionally with somearrangement (not shown) for extending and retracting the flexible memberF out of and into the CKAH structure. The flexibility of the extendedmember F allows the CKA, with the spring 41 in place to compensate fibrelength tolerances as aforementioned, to be fully inserted (arrow E3)into the ASA and rotated (arrow R) to lock it in position, followed byremoval of the spring 41 and retraction of the flexible member toreposition the spring in the CKAH ready for re-use in the next CKA to befitted.

1. A device for cleaving an optical fibre, comprising a fixing mechanismconfigured to fix a fixing element to the optical fibre, and a cleavingmechanism configured to cleave the optical fibre, the device comprisinga flexibly-positionable neck and clamp configured to temporarily attachthe device in a working position on a telecoms distribution frame orother apparatus where optical fibres are to be connected, and whereinthe fixing mechanism and cleaving mechanism are arranged such that thefibre is cleaved, and consequently an end face of the fibre is produced,at a preset position along the fibre with respect to the fixing elementand wherein the cleaving mechanism cleaves the fibre such that the fibreend face produced is oriented at a non-perpendicular angle with respectto a longitudinal axis of the fibre.
 2. A device according to claim 1,further comprising a hand-held tool.
 3. A device according to claim 1,wherein the fixing mechanism and the cleaving mechanism are mutuallyarranged such that the fibre end face produced by the cleaving mechanismis at a preset orientation with respect to the fixing element.
 4. Adevice according to claim 3, wherein the fixing mechanism includes anorientation determining means arranged to orient the fixing element at apredetermined orientation about the longitudinal axis of the fibre, withrespect to the cleaving mechanism.
 5. A device according to claim 4,wherein the orientation determining means comprises a non-circularorifice arranged to receive the fixing element therein, the fixingelement having a corresponding non-circular cross-section.
 6. A deviceaccording to claim 1, wherein the cleaving mechanism includes a scoringblade configured to score the fibre and cause a crack to propagatethrough the fibre to cleave the fibre, wherein the scoring bladeincludes a plurality of positions such that for each fibre, or set offibres that is cleaved by the device, a different one of the pluralityof positions on the blade is used to score the fibre.
 7. A device forcleaving an optical fibre, comprising a fixing mechanism configured tofix a fixing element to the optical fibre, and a cleaving mechanismconfigured to cleave the optical fibre, wherein a connector body holderis attached to the device to hold a connector body into which will beinserted a crimped ferrule and cleaved optical fibre prepared by use ofthe device and the connector body holder is rotatably attached to thedevice to enable insertion of a ferrule and fibre into each end of theconnector body from directions of insertion less than 180 degrees apart.8. A device according to claim 7, further comprising a hand-held tool.9. A device according to claim 7, wherein the fixing mechanism and thecleaving mechanism are arranged such that the fibre is cleaved, andconsequently an end face of the fibre is produced, at a preset positionalong the fibre with respect to the fixing element and wherein thecleaving mechanism cleaves the fibre such that the fibre end faceproduced is oriented at a non-perpendicular angle with respect to alongitudinal axis of the fibre.
 10. A device according to claim 9,wherein the fixing mechanism and the cleaving mechanism are mutuallyarranged such that the fibre end face produced by the cleaving mechanismis at a preset orientation with respect to the fixing element.
 11. Adevice according to claim 10, wherein the fixing mechanism includes anorientation determining means arranged to orient the fixing element at apredetermined orientation about the longitudinal axis of the fibre, withrespect to the cleaving mechanism.
 12. A device according to claim 11,wherein the orientation determining means comprises a non-circularorifice arranged to receive the fixing element therein, the fixingelement having a corresponding non-circular cross-section.
 13. A deviceaccording to claim 7, wherein the cleaving mechanism includes a scoringblade configured to score the fibre and cause a crack to propagatethrough the fibre to cleave the fibre, wherein the scoring bladeincludes a plurality of positions such that for each fibre, or set offibres that is cleaved by the device, a different one of the pluralityof positions on the blade is used to score the fibre.
 14. A device forcleaving an optical fibre, comprising a fixing mechanism configured tofix a fixing element to the optical fibre, and a cleaving mechanismconfigured to cleave the optical fibre, wherein a connector body holderis attached to the device to hold a connector body into which will beinserted a crimped ferrule and cleaved optical fibre prepared by use ofthe device, wherein the device comprises a ferrule assembly holderconfigured to hold a ferrule assembly of (i) the ferrule and (ii) thefibre to be cleaved and (iii) a ferrule holder, wherein the ferruleassembly holder is adapted to hold the ferrule assembly during a crimpand cleave operation and the device comprises a guide means attachedthereto, wherein the ferrule assembly holder is moveable on a controlledpath from a crimp-and-cleave position to bring the ferrule assembly intoalignment with a connector body when held in the connector body holderin use, and the ferrule assembly holder is then releaseable to enableinsertion and locking of the ferrule assembly into the connector body.15. A device according to claim 14, further comprising a hand-held tool.16. A device according to claim 14, wherein the fixing mechanism and thecleaving mechanism are arranged such that the fibre is cleaved, andconsequently an end face of the fibre is produced, at a preset positionalong the fibre with respect to the fixing element and wherein thecleaving mechanism cleaves the fibre such that the fibre end faceproduced is oriented at a non-perpendicular angle with respect to alongitudinal axis of the fibre.
 17. A device according to claim 16,wherein the fixing mechanism and the cleaving mechanism are mutuallyarranged such that the fibre end face produced by the cleaving mechanismis at a preset orientation with respect to the fixing element.
 18. Adevice according to claim 17, wherein the fixing mechanism includes anorientation determining means arranged to orient the fixing element at apredetermined orientation about the longitudinal axis of the fibre, withrespect to the cleaving mechanism.
 19. A device according to claim 18,wherein the orientation determining means comprises a non-circularorifice arranged to receive the fixing element therein, the fixingelement having a corresponding non-circular cross-section.
 20. A deviceaccording to claim 14, wherein the cleaving mechanism includes a scoringblade configured to score the fibre and cause a crack to propagatethrough the fibre to cleave the fibre, wherein the scoring bladeincludes a plurality of positions such that for each fibre, or set offibres that is cleaved by the device, a different one of the pluralityof positions on the blade is used to score the fibre.
 21. A device forcleaving an optical fibre, comprising a fixing mechanism configured tofix a fixing element to the optical fibre, and a cleaving mechanismconfigured to cleave the optical fibre, wherein a connector body holderis attached to the device to hold a connector body into which will beinserted a crimped ferrule and cleaved optical fibre prepared by use ofthe device, wherein the device comprises a ferrule assembly holderconfigured to hold a ferrule assembly of (i) the ferrule and (ii) thefibre to be cleaved and (iii) a ferrule holder, wherein the ferruleassembly holder is adapted to hold the ferrule assembly during a crimpand cleave operation, wherein the ferrule assembly holder is configuredto receive a succession of suitably shaped and arranged ferruleassemblies, and wherein the ferrule assembly holder carries a re-useableresiliently-compressible member configured to be inserted intosuccessive ferrule assemblies, between the end of the ferrule and afacing internal end of the ferrule holder, to compensate resiliently forcleaved fibre length tolerance variations during insertion of theferrule assemblies into connector bodies held in the connector bodyholder, and the compressible member is removable from the ferruleassemblies after insertion and locking of the ferrule assemblies intothe connector bodies.
 22. A device according to claim 21, wherein thecompressible member is attached to the ferrule assembly holder by aflexible member of sufficient length and flexibility to permit releaseof the ferrule assembly from the ferrule assembly holder and insertionand locking of the ferrule assembly into the connector body held in theconnector body holder in use while the compressible member is in placein the ferrule assembly.
 23. A device according to claim 22, furthercomprising retraction means for retracting the flexible member afterremoval of the compressible member from the ferrule assembly-tore-position the compressible member on the ferrule assembly holder forinsertion into the next ferrule assembly.
 24. A device according toclaim 21, further comprising a hand-held tool.
 25. A device according toclaim 21, wherein the fixing mechanism and the cleaving mechanism arearranged such that the fibre is cleaved, and consequently an end face ofthe fibre is produced, at a preset position along the fibre with respectto the fixing element and wherein the cleaving mechanism cleaves thefibre such that the fibre end face produced is oriented at anon-perpendicular angle with respect to a longitudinal axis of thefibre.
 26. A device according to claim 25, wherein the fixing mechanismand the cleaving mechanism are mutually arranged such that the fibre endface produced by the cleaving mechanism is at a preset orientation withrespect to the fixing element.
 27. A device according to claim 26,wherein the fixing mechanism includes an orientation determining meansarranged to orient the fixing element at a predetermined orientationabout the longitudinal axis of the fibre, with respect to the cleavingmechanism.
 28. A device according to claim 27, wherein the orientationdetermining means comprises a non-circular orifice arranged to receivethe fixing element therein, the fixing element having a correspondingnon-circular cross-section.
 29. A device according to claim 21, whereinthe cleaving mechanism includes a scoring blade configured to score thefibre and cause a crack to propagate through the fibre to cleave thefibre, wherein the scoring blade includes a plurality of positions suchthat for each fibre, or set of fibres that is cleaved by the device, adifferent one of the plurality of positions on the blade is used toscore the fibre.
 30. A device for cleaving an optical fibre, comprisinga fixing mechanism configured to fix a fixing element to the opticalfibre, and a cleaving mechanism configured to cleave the optical fibre,wherein a connector body holder is attached to the device to hold aconnector body into which will be inserted a crimped ferrule and cleavedoptical fibre prepared by use of the device, the device furthercomprising a securing means attached thereto for directly securing theferrule and the fibre during and after a crimp and cleave operation inthe absence of any separate ferrule holder.
 31. A device according toclaim 30 further comprising a transfer means configured such that thesecuring means and the secured crimped ferrule and cleaved fibre can bemoved and guided by a guide means attached to the device, (i) to bringthe ferrule and fibre from a crimp-and-cleave position into alignmentwith an connector body when held in the connector body holder in use and(ii) to insert the ferrule and fibre into the connector body in arequired orientation with or without a keying formation on the ferrule,the securing means being releasable after the ferrule has been fixed inthe connector body in the required orientation.
 32. A device accordingto claim 30, further comprising a hand-held tool.
 33. A device accordingto claim 30, wherein the fixing mechanism and the cleaving mechanism arearranged such that the fibre is cleaved, and consequently an end face ofthe fibre is produced, at a preset position along the fibre with respectto the fixing element and wherein the cleaving mechanism cleaves thefibre such that the fibre end face produced is oriented at anon-perpendicular angle with respect to a longitudinal axis of thefibre.
 34. A device according to claim 33, wherein the fixing mechanismand the cleaving mechanism are mutually arranged such that the fibre endface produced by the cleaving mechanism is at a preset orientation withrespect to the fixing element.
 35. A device according to claim 34,wherein the fixing mechanism includes an orientation determining meansarranged to orient the fixing element at a predetermined orientationabout the longitudinal axis of the fibre, with respect to the cleavingmechanism.
 36. A device according to claim 35, wherein the orientationdetermining means comprises a non-circular orifice arranged to receivethe fixing element therein, the fixing element having a correspondingnon-circular cross-section.
 37. A device according to claim 30, whereinthe cleaving mechanism includes a scoring blade configured to score thefibre and cause a crack to propagate through the fibre to cleave thefibre, wherein the scoring blade includes a plurality of positions suchthat for each fibre, or set of fibres that is cleaved by the device, adifferent one of the plurality of positions on the blade is used toscore the fibre.
 38. A method of coupling optical fibres using a devicecomprising a fixing mechanism configured to fix a fixing element to anoptical fibre, and a cleaving mechanism configured to cleave the opticalfibre, the method comprising: (a) directly securing a ferrule and afibre in a securing means during and after a crimp and cleave operationin the absence of any separate ferrule holder, (b) moving the securedcrimped ferrule and cleaved fibre (i) to bring the ferrule and fibrefrom the crimp-and-cleave position into alignment with a connector bodywhen held in a connector body holder and (ii) to insert the ferrule andfibre into the connector body in a required orientation with or withouta keying formation on the ferrule, (c) fixing the ferrule and fibre inthe connector body in the required orientation, and then (d) releasingthe securing means.